To Walk Without Thought

This essay by Floss Willcocks was commended by the judges of the renowned Newnham College, Cambridge, Engineering Prize essay competition.

Question: Select some interesting industry (in decline, or thriving) or engineering construction (historical or contemporary), either local or that you have come to know about, and outline and discuss the physical phenomena and scientific and/or engineering principles it is based upon or applies.

I was inspired by a new milestone in biomedical engineering that was reached this Summer involving the development of bionic limbs - an industry which thrives today in a society with an ever-increasing demand for its development and production.

The first-ever bionic prosthetic leg controlled purely by subconscious thought was announced in May by the Icelandic biomedical company Össur, a feat never successfully achieved before now. People who suffer horrific accidents, permanent birth deformities or incurable diseases often believe that they will never walk normally again when their only option is amputation. However, it might soon be possible for many amputees to access new technology so advanced that they will be able to live a normal life again; to work in everyday jobs, to support families and to achieve physically what was previously thought unobtainable in their condition.

So why did engineering play such a key part in this breakthrough? The answer is because engineering plays a key part in every aspect of life, often without us even realising. Any industry that thrives does so because it is improving. It improves because it evolves, and just like Charles Darwin proposed, it evolves because something is developed which does a job better, and therefore outdoes the competition. It's just like natural selection, except instead of better qualities stemming from the random mutation of DNA, the beneficial characteristic is designed by the engineers in order to solve a problem, which leads me onto what engineers really are...

Engineers are problem solvers. They are given a problem by the contractors, doctors, and politicians, and then given the theoretical equipment for solving the problem by the physicists, chemists and mathematicians, but it is their role which is the vital one. They have the metaphorical toolkit of scientific creativity and experience which they use like hammers and spanners to build the solution, and it is these engineers who link together all other areas of research by giving them a mutual applied practical purpose. Problem solving benefits us all, especially when it comes to personal medical assistance and, in turn, as long as there are engineers to support its branches; this industry will always thrive.

If you need further convincing that this scientific breakthrough is one of the most impressive and exciting developments in biomedical engineering of this decade, you only needs to picture yourself in the role of one of these top-level engineers. You have the equipment; it consists of a degree in problem-solving, years of applied experience in biomedicine, the latest design software and all the biological details of the human leg - a system so old and basic, it has been I used without fault since six million years ago when men first stood on two feet. Your task - to build a replacement. Surely it can't be that difficult in our modern world of technology - even if we are not talking about the antiquated wooden leg, which might have served its duty in the earlier days but is now truly discredited thanks to the pirate stereotype. You think of Asimo, the most advanced humanoid built by Honda. This robot’s legs were designed to replicate as realistically as possible the movements of a human’s. The way we shift our weight using our bodies was vital to ensuring the balance mechanism of Asimo was successful. His hip, knee and ankle joints allow what Honda refer to as “degrees of freedom” within the body of Asimo. A single “degree” allows a movement either left, right, up or down, and out of the 32 separate “degrees” throughout his body (excluding the hands), seven are found within each leg. This was calculated as an approximate range of the human legs after detailed research into human joint movement, and as a result, this robot is able to run upstairs, play football and even dance to disco music.

So surely your problem is already solved, you say. If we already know how to replicate each action that the legs need to perform, can't we all have Asimo’s legs? What is the difference between the robotic and the prosthetic?

https://asimo.honda.com/asimo-specs/

Essentially, there is a huge difference. In order for the legs to function just like any human’s would, they need to control themselves by means of reflexes triggered by the spinal cord rather than direct commands from the brain. Asimo has a “brain” (inner computing system) which tells his legs exactly what to do; every circuit and every connection is a thought-through process. As humans, we can put on a pair of socks without being aware of what a complex series of movements we execute with the foot and ankle. If we had to think through every minute movement the process would be a lengthy and tiring one, and we don't appreciate how the leg and foot just somehow do what they’re supposed to do. Without this consistent automatic adjustment by our neuromuscular system, clearing a doorstep without stumbling becomes a major accomplishment.

It is for this reason that upper limb bionics have always been one step ahead. Upper limbs use more conscious control than the lower ones. We use arms and hands for actually doing things like picking up a cup or working a screwdriver, so we do a lot of the heavy work of coordination. By contrast, we use legs for getting around and our control is much less conscious. Essentially, the legs need to control themselves by means of reflexes triggered by the spinal cord rather than direct commands from the brain. The actual movements of the leg are no more complicated than those of our arms and hands, but it is recreating the way we tell our muscles to move them that was the prodigious breakthrough from the Icelandic engineering firm this Summer.

After coming to grips with how complicated this problem was, trying to understand the complexities of the solution will astound you tenfold. Össur’s research and development for this latest mind-controlled prosthetics project was spearheaded by Dr. Thorvaldur Ingvarsson, M.D., Ph.D. He and his team analysed the way our muscles respond to our surroundings, concluding that the subconscious movements in able-bodied individuals, are triggered by electrical impulses inside the body that catalyze the appropriate muscles into action. These bypass the brain entirely, which is why you do not notice yourself consistently altering your position or your weight distribution to ensure you do not just topple over every time you take a step.

https://www.ossur.com/about-ossur/news-from-ossur/1396-ossur-introduces-first-mind-controlled-bionic-prosthetic-lower-limbs-for-amputees

Össur’s inner bionic control system replicates this by means of Implanted MyoElectric Sensors (IMES), the size of matchsticks, implanted into specific remnant muscles in the limb stump. Meanwhile, a coiled-wire receiver inside the prosthesis picks up the impulses and transmits them wirelessly to the robotic limb's inner computer. Together, the IMES and robotic limb act as a sort cybernetic spinal cord, bypassing the brain and functioning entirely within the lower half of the body. Instead of the wearer consciously controlling the limb's movements, an unconscious command is sent to the prosthesis by an interior processor when certain stimuli are detected, which in turn sends the commands to control the movement.

https://www.ossur.com/about-ossur/news-from-ossur/1396-ossur-introduces-first-mind-controlled-bionic-prosthetic-lower-limbs-for-amputees

On a side note, further fascinating developments in bionics have resulted in remarkable replacements for other complex muscle systems too - particularly the human hand. Our hands have 29 separate bones and joints requiring 34 different muscles to move them, and at least 123 named ligaments (unlucky for those hoping to study medicine!) - but even more unlucky for those who have had accidents, birth deformities or diseases which have negated the use of one of the most important musculoskeletal systems in our body. With modern technology, there are hand prosthetics which can not only be controlled by the brain, but even send impulses back to it, allowing the patient to feel and touch again.

https://theinstitute.ieee.org/technology-focus/technology-topic/prosthetic-limbs-offer-a-sense-of-touch

There is a pressing matter which must be addressed as this industry continues to thrive and excel in the midst of modern day issues. The drive behind the urgency to develop prosthetic limbs I fear is coming from the wrong side of society. This thought came to me as I began to consider who it really is all for? Who in society is demanding the need to regain mobility? Who will be the chief benefactors from generations of research and design? Who will wear the world's most impressive, most expensive, most ingenious pair of legs? I would like to say that it will be those who have earned and deserve the right to walk again. Everyone can agree that those who have suffered trauma to their lower limbs due to accidental life-changing incidents or illnesses have not inflicted this way of life on themselves. They deserve to live normally again. Nerve-damaging cancers create disruption to a patient's life on a whole new level when a limb must be entirely removed as part of the already gruelling chemotherapeutic treatments. How about those who have been born with leg-deformities? Those who have never even had the chance to walk at all?

Unfortunately the overwhelming majority of lower limb amputees have had to have the procedure due to diseases such as Diabetes Mellitus and Atherosclerosis. These two diseases alone combine to cause almost 90% of all leg amputations in the UK, and they develop in the body primarily by excessive consumption of alcohol, cigarettes, and by poor diet. An average of 135 amputations each week due to diabetes are currently carried out in England alone.

When the Red Cross reports that worldwide 800 people die every month from damage to limbs caused by uncleared explosives... 10% of these being children, it becomes clear that in countries where the amputations themselves are not even safe, this much needed technology is a long, long way away. When the average age for lower limb amputation in England is over 70, and 1.2 billion people live on just 82 pence a day, you do not have to be a scientist to guess where the majority of these ingenious and expensive bionic legs will end up when they become more widely available in the future.

On the other hand, however, it can be argued that the excessive demand for limb prosthetics is beneficial for the industry. These overwhelming figures make the financial value and efficiency of bionic production far more significant. Perhaps large industrial companies such as Össur would never have been able to fund the research and development of their new breakthrough prosthetic without the demand for over 7,000 specifically designed lower limb replacements per year across the country. Just as the industry of fuel-efficiency and renewable energy production expands more than ever to produce state of the art technologies and discoveries (hydroelectric systems, low emission fuels, mass recycling systems etc), these revelations used to improve our everyday lifestyle and the environment around us would never have been discovered, if selfish man had not depleted, exploited and abused the planet's natural resources to the point of desperation in the first place. The fact that our way of life has become so reliant on unsustainable sources drove us into action. The realisation that soon there just will not be enough oil, coal, gas, space, food, clean water, indeed anything left for the ever-growing population was the one impetus that the human race needed to progress further with our engineering abilities. Who knows what could be discovered with the help of global disaster…?

All this has led me to look at the horrifying statistics now with a far more open-minded and optimistic point of view, but when it comes back to the point of my article, I revert back to my original thesis. In an ideal world anyone and everyone should benefit from the products of these hard-working teams of engineers, designers and manufacturers, but for the immediate future it seems that just won't be the case. However, I write this extended essay with the primary intention to inspire and publicise the achievements of the thriving bionic limb industry, and so now let me express exactly why this field of engineering excites me so much.

The more I learnt about this industry, the more impressive I perceived it to be, and it is for this reason that I am so keen to spread awareness of this ingenuity in as many forms as possible. I strive to take up one day a key role in biomedical development, as it is a career path such as this which I am very keen to study at University. However, it will be many years yet before I have acquired sufficient knowledge and experience to contribute directly to this industry about which I am so passionate. For now, there are ways in which I can help in another equally significantly forms; firstly by supporting the charities which fund this research, and by sharing the knowledge I have of what engineers can do, given the chance. This essay is one way I can spread awareness; telling friends, sharing achievements and publishing articles are others. If more people know about what could be done, more can be done.

I can only conclude by saying that this ever-developing area of research and design will never cease to fascinate and impress me. Engineering has grown to the point where people who have lost the ability to use a vital part of their body, can now drive, run, cycle, cook, clean, work, live like any able-bodied person, and that is an incredible achievement. There are nerves all over the human body, and when a person's arm or leg is severed or paralysed thousands of connections are permanently broken. The human race, in the space of just a few generations, has built devices that can connect to a human brain and function almost as efficiently as a limb made of flesh and muscle and blood. This is just a tiny subsection of the many industries which continue to thrive and grow thanks to the work of engineers. They are the reason we have cars, clothes, running water, refrigerators, shower gel; everything we use in our day to day lives.

...And it's not over yet.

What will be next?